The discussion below is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.
Aspects of the present disclosure relate to a method of monitoring aspects of a well pumping system while operating and/or optimizing the performance of the well pumping system, and a system for monitoring aspects of the system while operating and/or optimizing the performance of the well pumping system. One industry where the monitoring of the pump jack system is in the exploration and production of oil in an oil field. However, a pump jack system can also be utilized in other industries besides the production of oil.
When a pump jack system is installed, a down-hole pump assembly is secured to a sucker rod and positioned within the well. A polished rod (sucker rod carrier) is attached to the sucker rod where the polished rod moves through a casing head at the ground level of the hole and a stuffing box. The stuffing box provides a seal and prevents oil from exiting between the interface between the stuffing box and the polished rod.
A bridle bar is coupled to an upper end of the polished rod and also to an end (commonly referred to as a horsehead) of the pump jack system with a plurality of cables (bridle). The position of the bridle bar and the sucker rod carrier are manually adjusted relative to each other on the pump jack to obtain maximum pump stroke of the sucker rod without striking the bottom of the well with the down-hole pump assembly. Once the optimum position of the polished rod and bridle bar are determined, the position of the polished rod and the bridle bar are fixed, typically with a clamp positioned about a circumference of the polished rod, or some other frictional engagement.
Over time, the clamp that is secured to the polished rod has a tendency of working loose or moving on the polished rod, or the down rod string stretches, which can adversely affect the performance of the well. The movement of the clamp on the polished rod causes the polished rod to move downward relative to the bridle bar. When the polished rod moves downwardly relative to the bridle bar, the down-hole section of the pump can strike the bottom of the well on the down stroke of the pump jack, which is commonly referred to as bottoming out. This action reduces the amount of oil produced with each pump cycle and can cause damage to the pumping system from the shock or impact caused by the down-hole section hitting the bottom as well.
When the down-hole section strikes the bottom of the well, the downward movement of the sucker rod and the polished rod is abruptly stopped. However, the bridle bar continues to move downwardly until the pump jack completes the downward stroke. As the pump jack reverses direction and moves in its upward stroke, the bridle bar moves upwardly quickly because there is no resistance from the sucker rod or the down-hole pump assembly. At some point during the upward stroke, the bridle bar re-engages the clamp attached to the polished rod and causes additional shock to the pump jack system due to the impact between the bridle bar and the clamp attached to the polished rod.
The operation of the jack pump system can also be adversely affected when the movement of the polished rod through the stuffing box and/or the well casing and/or the rod guides becomes restricted or the downward movement of the sucker rod and/or the down-hole pump assembly becomes impeded. When the downward movement of any of the polished rod, the sucker rod or the down-hole pump assembly becomes impeded, the bridle bar will move downwardly at a faster rate than the polished rod and separate from the clamp attached to the polished rod. When the jack pump moves in the upward stroke, the bridle bar will move upwardly quickly until the bridle bar re-engages the clamp which causes a sudden deceleration and has the similar detrimental effects as when the down-hole pump assembly strikes the bottom of the well.